Wave Runup on Atoll Reefs
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This Keyword List Contains Indian Ocean Place Names of Coral Reefs, Islands, Bays and Other Geographic Features in a Hierarchical Structure
CoRIS Place Keyword Thesaurus by Ocean - 8/9/2016 Indian Ocean This keyword list contains Indian Ocean place names of coral reefs, islands, bays and other geographic features in a hierarchical structure. For example, the first name on the list - Bird Islet - is part of the Addu Atoll, which is in the Indian Ocean. The leading label - OCEAN BASIN - indicates this list is organized according to ocean, sea, and geographic names rather than country place names. The list is sorted alphabetically. The same names are available from “Place Keywords by Country/Territory - Indian Ocean” but sorted by country and territory name. Each place name is followed by a unique identifier enclosed in parentheses. The identifier is made up of the latitude and longitude in whole degrees of the place location, followed by a four digit number. The number is used to uniquely identify multiple places that are located at the same latitude and longitude. For example, the first place name “Bird Islet” has a unique identifier of “00S073E0013”. From that we see that Bird Islet is located at 00 degrees south (S) and 073 degrees east (E). It is place number 0013 at that latitude and longitude. (Note: some long lines wrapped, placing the unique identifier on the following line.) This is a reformatted version of a list that was obtained from ReefBase. OCEAN BASIN > Indian Ocean OCEAN BASIN > Indian Ocean > Addu Atoll > Bird Islet (00S073E0013) OCEAN BASIN > Indian Ocean > Addu Atoll > Bushy Islet (00S073E0014) OCEAN BASIN > Indian Ocean > Addu Atoll > Fedu Island (00S073E0008) -
A Field Experiment on a Nourished Beach
CHAPTER 157 A Field Experiment on a Nourished Beach A.J. Fernandez* G. Gomez Pina * G. Cuena* J.L. Ramirez* Abstract The performance of a beach nourishment at" Playa de Castilla" (Huel- va, Spain) is evaluated by means of accurate beach profile surveys, vi- sual breaking wave information, buoy-measured wave data and sediment samples. The shoreline recession at the nourished beach due to "profile equilibration" and "spreading out" losses is discussed. The modified equi- librium profile curve proposed by Larson (1991) is shown to accurately describe the profiles with a grain size varying across-shore. The "spread- ing out" losses measured at " Playa de Castilla" are found to be less than predicted by spreading out formulations. The utilization of borrowed material substantially coarser than the native material is suggested as an explanation. 1 INTRODUCTION Fernandez et al. (1990) presented a case study of a sand bypass project at "Playa de Castilla" (Huelva, Spain) and the corresponding monitoring project, that was going to be undertaken. The Beach Nourishment Monitoring Project at the "Playa de Castilla" was begun over two years ago. The project is being *Direcci6n General de Costas. M.O.P.T, Madrid (Spain) 2043 2044 COASTAL ENGINEERING 1992 carried out to evaluate the performance of a beach fill and to establish effective strategies of coastal management and represents one of the most comprehensive monitoring projects that has been undertaken in Spain. This paper summa- rizes and discusses the data set for wave climate, beach profiles and sediment samples. 2 STUDY SITE & MONITORING PROGRAM Playa de Castilla, Fig. 1, is a sandy beach located on the South-West coast of Spain between the Guadiana and Gualdalquivir rivers. -
Observations of Nearshore Infragravity Waves: Seaward and Shoreward Propagating Components A
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 107, NO. C8, 3095, 10.1029/2001JC000970, 2002 Observations of nearshore infragravity waves: Seaward and shoreward propagating components A. Sheremet,1 R. T. Guza,2 S. Elgar,3 and T. H. C. Herbers4 Received 14 May 2001; revised 5 December 2001; accepted 20 December 2001; published 6 August 2002. [1] The variation of seaward and shoreward infragravity energy fluxes across the shoaling and surf zones of a gently sloping sandy beach is estimated from field observations and related to forcing by groups of sea and swell, dissipation, and shoreline reflection. Data from collocated pressure and velocity sensors deployed between 1 and 6 m water depth are combined, using the assumption of cross-shore propagation, to decompose the infragravity wave field into shoreward and seaward propagating components. Seaward of the surf zone, shoreward propagating infragravity waves are amplified by nonlinear interactions with groups of sea and swell, and the shoreward infragravity energy flux increases in the onshore direction. In the surf zone, nonlinear phase coupling between infragravity waves and groups of sea and swell decreases, as does the shoreward infragravity energy flux, consistent with the cessation of nonlinear forcing and the increased importance of infragravity wave dissipation. Seaward propagating infragravity waves are not phase coupled to incident wave groups, and their energy levels suggest strong infragravity wave reflection near the shoreline. The cross-shore variation of the seaward energy flux is weaker than that of the shoreward flux, resulting in cross-shore variation of the squared infragravity reflection coefficient (ratio of seaward to shoreward energy flux) between about 0.4 and 1.5. -
Mapping Turbidity Currents Using Seismic Oceanography Title Page Abstract Introduction 1 2 E
Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Ocean Sci. Discuss., 8, 1803–1818, 2011 www.ocean-sci-discuss.net/8/1803/2011/ Ocean Science doi:10.5194/osd-8-1803-2011 Discussions OSD © Author(s) 2011. CC Attribution 3.0 License. 8, 1803–1818, 2011 This discussion paper is/has been under review for the journal Ocean Science (OS). Mapping turbidity Please refer to the corresponding final paper in OS if available. currents using seismic E. A. Vsemirnova and R. W. Hobbs Mapping turbidity currents using seismic oceanography Title Page Abstract Introduction 1 2 E. A. Vsemirnova and R. W. Hobbs Conclusions References 1Geospatial Research Ltd, Department of Earth Sciences, Tables Figures Durham University, Durham DH1 3LE, UK 2Department of Earth Sciences, Durham University, Durham DH1 3LE, UK J I Received: 25 May 2011 – Accepted: 12 August 2011 – Published: 18 August 2011 J I Correspondence to: R. W. Hobbs ([email protected]) Published by Copernicus Publications on behalf of the European Geosciences Union. Back Close Full Screen / Esc Printer-friendly Version Interactive Discussion 1803 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Abstract OSD Using a combination of seismic oceanographic and physical oceanographic data ac- quired across the Faroe-Shetland Channel we present evidence of a turbidity current 8, 1803–1818, 2011 that transports suspended sediment along the western boundary of the Channel. We 5 focus on reflections observed on seismic data close to the sea-bed on the Faroese Mapping turbidity side of the Channel below 900m. Forward modelling based on independent physi- currents using cal oceanographic data show that thermohaline structure does not explain these near seismic sea-bed reflections but they are consistent with optical backscatter data, dry matter concentrations from water samples and from seabed sediment traps. -
USER MANUAL SWASH Version 7.01
SWASH USER MANUAL SWASH version 7.01 SWASH USER MANUAL by : TheSWASHteam mail address : Delft University of Technology Faculty of Civil Engineering and Geosciences Environmental Fluid Mechanics Section P.O. Box 5048 2600 GA Delft The Netherlands website : http://www.tudelft.nl/swash Copyright (c) 2010-2020 Delft University of Technology. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back- Cover Texts. A copy of the license is available at http://www.gnu.org/licenses/fdl.html#TOC1. iv Contents 1 About this manual 1 2 Generaldescriptionandinstructionsforuse 3 2.1 Introduction................................... 3 2.2 Background,featuresandapplications . ...... 3 2.2.1 Objectiveandcontext ......................... 3 2.2.2 Abird’s-eyeviewofSWASH. 4 2.2.3 ModelfeaturesandvalidityofSWASH . 7 2.2.4 Relation to Boussinesq-type wave models . .... 8 2.2.5 Relation to circulation and coastal flow models. ...... 9 2.3 Internal scenarios, shortcomings and coding bugs . ......... 9 2.4 Unitsandcoordinatesystems . 10 2.5 Choiceofgridsandtimewindows . .. 11 2.5.1 Introduction............................... 11 2.5.2 Computationalgridandtimewindow . 12 2.5.3 Inputgrid(s)andtimewindow(s) . 13 2.5.4 Input grid(s) for transport of constituents . ...... 14 2.5.5 Outputgrids .............................. 15 2.6 Boundaryconditions .............................. 16 2.7 Timeanddatenotation ............................ 17 2.8 Troubleshooting................................. 17 3 Input and output files 19 3.1 General ..................................... 19 3.2 Input/outputfacilities . .. 19 3.3 Printfileanderrormessages . .. 20 4 Description of commands 21 4.1 Listofavailablecommands. -
Coastal Landform Processes 29/03/2018 Do Now Copy Below: When Waves Lose Energy Material Is Deposited
Coastal Landform Processes 29/03/2018 Do Now Copy below: When waves lose energy material is deposited. This typical happens in sheltered areas such as bays, this explains why beaches are found here. Wave refraction is where the energy of the wave is reduced Aim ▪ To understand process acting on the coast that lead to landforms Wave energy converges on the headlands Wave energy is diverged Wave energy converges on the headlands Sediment moves and is deposited http://www.bbc.co.uk/education/cli ps/zsmb4wx Erosion Destructive waves will erode the coastline in four different ways: 1. Hydraulic Power Complete your 2. Corrasion erosion sheet 3. Attrition 4. Corrosion 5. Abrasion Longshore Drift • “Longshore drift is a process by which sediments such as sand or other materials are transported along a beach.” • The general direction of longshore drift around the coasts of the British Isles is controlled by the direction of the dominant wind. http://www.bbc.co.uk/learningzo ne/clips/the-coastline- longshore-drift-and- spits/3086.html Longshore Drift: A bird’s eye view Cliff Beach Sea Longshore Drift: A bird’s eye view Cliff Eroded material Beach from the cliffs is left on the beach Bob the pebble Sea Longshore Drift: A bird’s eye view Cliff Beach Waves The waves from the sea come onto the beach at an angle and pick Bob and other material up and move them up the beach. Sea Longshore Drift: A bird’s eye view Cliff Beach Swash This movement of the waves is called SWASH. The waves come in at an angle due to Sea wind direction Longshore Drift: A bird’s eye view Cliff Beach The waves then move back down the beach in a straight Swash direction due to gravity. -
3.2.6. Methods for Field Measurement and Remote Sensing of the Swash Zone
© Author(s) 2014. CC Attribution 4.0 License. ISSN 2047-0371 3.2.6. Methods for field measurement and remote sensing of the swash zone Sebastian J. Pitman1 1 Ocean and Earth Sciences, National Oceanography Centre, University of Southampton ([email protected]) ABSTRACT: Swash action is the dominant process responsible for the cross-shore exchange of sediment between the subaerial and subaqueous zones, with a significant part of the littoral drift also taking place as a result of swash motions. The swash zone is the area of the beach between the inner surfzone and backbeach that is intermittently submerged and exposed by the processes of wave uprush and backwash. Given the dominant role that swash plays in the morphological evolution of a beach, it is important to understand and quantify the main processes. The extent of swash (horizontally and vertically), current velocities and suspended sediment concentrations are all parameters of interest in the study of swash processes. In situ methods of measurements in this energetic zone were instrumental in developing early understanding of swash processes, however, the field has experienced a shift towards remote sensing methods. This article outlines the emergence of high precision technologies such as video imaging and LIDAR (light detection and ranging) for the study of swash processes. Furthermore, the applicability of these methods to large-scale datasets for quantitative analysis is demonstrated. KEYWORDS: run-up, morphodynamics, coastal imaging, video, LIDAR. Introduction al., 2004) and its dominant responses are largely well understood. It is the most The beachface is a highly spatially and energetic zone in terms of bed sediment temporally dynamic zone, predominantly due movement and is characterised by strong and to swash processes such as wave run up. -
Infragravity Wave Energy Partitioning in the Surf Zone in Response to Wind-Sea and Swell Forcing
Journal of Marine Science and Engineering Article Infragravity Wave Energy Partitioning in the Surf Zone in Response to Wind-Sea and Swell Forcing Stephanie Contardo 1,*, Graham Symonds 2, Laura E. Segura 3, Ryan J. Lowe 4 and Jeff E. Hansen 2 1 CSIRO Oceans and Atmosphere, Crawley 6009, Australia 2 Faculty of Science, School of Earth Sciences, The University of Western Australia, Crawley 6009, Australia; [email protected] (G.S.); jeff[email protected] (J.E.H.) 3 Departamento de Física, Universidad Nacional, Heredia 3000, Costa Rica; [email protected] 4 Faculty of Engineering and Mathematical Sciences, Oceans Graduate School, The University of Western Australia, Crawley 6009, Australia; [email protected] * Correspondence: [email protected] Received: 18 September 2019; Accepted: 23 October 2019; Published: 28 October 2019 Abstract: An alongshore array of pressure sensors and a cross-shore array of current velocity and pressure sensors were deployed on a barred beach in southwestern Australia to estimate the relative response of edge waves and leaky waves to variable incident wind wave conditions. The strong sea 1 breeze cycle at the study site (wind speeds frequently > 10 m s− ) produced diurnal variations in the peak frequency of the incident waves, with wind sea conditions (periods 2 to 8 s) dominating during the peak of the sea breeze and swell (periods 8 to 20 s) dominating during times of low wind. We observed that edge wave modes and their frequency distribution varied with the frequency of the short-wave forcing (swell or wind-sea) and edge waves were more energetic than leaky waves for the duration of the 10-day experiment. -
Assessing Long-Term Changes in the Beach Width of Reef Islands Based on Temporally Fragmented Remote Sensing Data
Remote Sens. 2014, 6, 6961-6987; doi:10.3390/rs6086961 OPEN ACCESS remote sensing ISSN 2072-4292 www.mdpi.com/journal/remotesensing Article Assessing Long-Term Changes in the Beach Width of Reef Islands Based on Temporally Fragmented Remote Sensing Data Thomas Mann 1,* and Hildegard Westphal 1,2 1 Leibniz Center for Tropical Marine Ecology, Fahrenheitstrasse 6, D-28359 Bremen, Germany; E-Mail: [email protected] 2 Department of Geosciences, University of Bremen, D-28359 Bremen, Germany * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +49-421-2380-0132; Fax: +49-421-2380-030. Received: 30 May 2014; in revised form: 7 July 2014 / Accepted: 18 July 2014 / Published: 25 July 2014 Abstract: Atoll islands are subject to a variety of processes that influence their geomorphological development. Analysis of historical shoreline changes using remotely sensed images has become an efficient approach to both quantify past changes and estimate future island response. However, the detection of long-term changes in beach width is challenging mainly for two reasons: first, data availability is limited for many remote Pacific islands. Second, beach environments are highly dynamic and strongly influenced by seasonal or episodic shoreline oscillations. Consequently, remote-sensing studies on beach morphodynamics of atoll islands deal with dynamic features covered by a low sampling frequency. Here we present a study of beach dynamics for nine islands on Takú Atoll, Papua New Guinea, over a seven-decade period. A considerable chronological gap between aerial photographs and satellite images was addressed by applying a new method that reweighted positions of the beach limit by identifying “outlier” shoreline positions. -
Climate Change Report for Gulf of the Farallones and Cordell
Chapter 6 Responses in Marine Habitats Sea Level Rise: Intertidal organisms will respond to sea level rise by shifting their distributions to keep pace with rising sea level. It has been suggested that all but the slowest growing organisms will be able to keep pace with rising sea level (Harley et al. 2006) but few studies have thoroughly examined this phenomenon. As in soft sediment systems, the ability of intertidal organisms to migrate will depend on available upland habitat. If these communities are adjacent to steep coastal bluffs it is unclear if they will be able to colonize this habitat. Further, increased erosion and sedimentation may impede their ability to move. Waves: Greater wave activity (see 3.3.2 Waves) suggests that intertidal and subtidal organisms may experience greater physical forces. A number of studies indicate that the strength of organisms does not always scale with their size (Denny et al. 1985; Carrington 1990; Gaylord et al. 1994; Denny and Kitzes 2005; Gaylord et al. 2008), which can lead to selective removal of larger organisms, influencing size structure and species interactions that depend on size. However, the relationship between offshore significant wave height and hydrodynamic force is not simple. Although local wave height inside the surf zone is a good predictor of wave velocity and force (Gaylord 1999, 2000), the relationship between offshore Hs and intertidal force cannot be expressed via a simple linear relationship (Helmuth and Denny 2003). In many cases (89% of sites examined), elevated offshore wave activity increased force up to a point (Hs > 2-2.5 m), after which force did not increase with wave height. -
Under Pressure Coastal Stack & Stump: Sediment Are Thrown Against Weathering (Freeze- the Cliffs by Waves
Tides: UP1 –Waves & Tides Constructive Waves: Longshore Drift: Transportation: • These are the rise and fall of the sea level, due • Traction: mainly to the pull of the moon • Strong swash and weak backwash that • Waves approach the beach at an angle due Large boulders and sediments • As the moon travels around the Earth, it push sand and pebbles up the beach to the prevailing wind direction are rolled along the sea bed. attracts the sea and pulls it upwards. The sun • Low waves with longer gaps between the • As the wave breaks, the swash carries They are too heavy to be helps too – but its much further away. So its crests (6-8 per min – low frequency) material up the beach at the same angle pull is not as strong. • Under 1m (oblique angle) as the prevailing wind picked up fully by the waves. • High tide occurs about every 12 and ½ hours, • Known as spilling waves as they ‘spill’ up • The backwash carries material back down with low tides in between. The difference the beach the beach at a right angle (90o) due to • Saltation: between the high and low tide is called the tidal • Gently sloping wave front gravity where small pieces of shingle range • Formed by storms often 100s KMs away • This means that material is moved along the or large sand grains are • Gentle beach beach in a zig zag route bounced along the sea bed. Waves: Destructive Waves: • Suspension: • Are formed by wind that blows over the sea, friction with the surface of water causes • Weak swash and strong backwash pulling small particles such as silts ripples to form and these develop into waves. -
ENVIRONMENT in COASTAL ENGINEERING: DEFINITIONS and EXAMPLES** Cyril Galvin, M. ASCE* ABSTRACT in Current Usage, Environmental A
ENVIRONMENT IN COASTAL ENGINEERING: DEFINITIONS AND EXAMPLES** Cyril Galvin, M. ASCE* ABSTRACT In current usage, environmental aspects of coastal engineering design include aspects of ecology and aesthe- tics, as well as environment. In practice, the aspect of environment is a limited one, considering man's surround- ings, with the works of man left out. The increased consid- eration of environmental aspects over the past 15 years has brought real benefits to the coastal engineering profession, as well as obvious problems. One problem is a mythology of coastal processes that has become widely accepted. Priori- ties in coastal engineering design remain a structure that will last a useful lifetime and perform its intended func- tion without creating new problems. After satisfying these fundamental requirements, the structure should minimize ecological change, and fit pleasingly in its setting. INTRODUCTION Design and THE Environment. A coastal structure must remain standing when hit by the most severe waves, currents, and winds that can reasonably be expected during its intended lifetime. Waves, currents, and winds are basic elements of the physical environment. In this structural sense, good coastal engineering is always sensitive to the environment. But the designer who creates a structure that doesn't fall down has not necessarily solved a coastal problem. The structure must also perform a function, without creating significant new problems. it must reduce beach erosion, prevent flooding, maintain a channel, provide a quiet anchorage, convey liquids across the shore, or serve other functions. There are groins standing out at sea after the beach has eroded away; jetties exist that enclose a deposit of sand rather than a navigable waterway; some seawalls are regularly overtopped by moderate seas; water intakes are silted in.